That article does contain the correct answer, so thank you very much for finding it, although the passage you've quoted is ChatGPT gibberish not in the source given.

Per https://iep.unibocconi.eu/europes-internal-tariffs-why-imfs-..., the model treats shopping local as evidence of the existence of a trade barrier, as opposed to a rational preference based on cultural and environmental considerations. This is why the numbers are ridiculously high. (Is there a 120% implicit tariff for textiles? Or do people just prefer warm clothes in the north and breezy clothes in the Mediterranean?)